AUSTIN (KXAN) — There is no shortage of trees and shrubs around the state that will have your eyes watering and your nose running. But with such a wide variety of flora spanning the Lone Star State, it can be difficult to determine which tree is the culprit behind your anguish.

So you can put a face to your enemy, we talked to Woodland Ecologist Karl Flocke from Texas A&M to find out which trees at what times of year emit the gunk that has you in a funk. 


If you are living in Central Texas during the winter months, you’ll undoubtedly hear people complaining about the dreaded cedar fever – the allergic response to cedar pollen, which can cause itchy eyes, sneezing, fatigue, sinus pressure and a runny nose. 

There are seven types of cedar in Texas. The Ashe juniper is most common in Central Texas and pollinates in December and January. Shortly after the Ashe tapers off, the eastern red cedars, found in North and East Texas, begin pollinating in February and end in March. 

The symptoms brought on by cedar pollination in the winter may stand out because there isn’t much else pollinating during this time.

While cedar allergies in December and January can be particularly rough on Central Texans, cedar pollen emitted by the Ashe juniper can affect the entire state.

“The pollen from those trees actually gets windblown all the way into South and East Texas. And they’re even records indicating pollen traveled from Central Texas all the way up towards Tulsa, Oklahoma.”

Unlike other tree pollen, cedar is extremely granular, which is why it can travel so far. 

“A male ash juniper can produce something like 500 billion little individual grains of pollen,” Flocke said.


Unlike the winter, several trees are pollinating in the spring. 

Flocke said the trees causing the most severe allergenic issues during this time in Texas are ash, elm, oak, pecan and pine. Unlike cedar, these trees tend to have pollen of a larger size, meaning you have to be close to the tree to be affected by the pollen.

The Texas ash tree occurs from Dallas to Central Texas, generally west of the Edwards Plateau. There is also the Carolina ash found in the more humid regions of East Texas and the Gregg ash in the far west portion of the state.

In Central Texas, the live oak tree’s pollination period peaks towards the end of March. These trees occur mostly east of the Balcones Escarpment but have been planted all over the state for landscape purposes. 

“Most folks that have a car and park it under a live oak tree will tell you that end of March, every single morning, you got to go outside and wash your window. Otherwise, you can’t see out of it. The pollen is so thick on most vehicles that time of year,” Flocke said. 

Elm and pecan trees also pollinate in the springtime. The elm is distributed widely across East, South and Central Texas. Pecan trees are found in similar areas and have been planted widely for landscape reasons.

Then there are the pine trees that can also be allergenic. Pines are found mostly on the eastern side of Texas.

If those trees are not enough, there are also various grasses, flowers and molds activating across the state during the spring, causing allergic reactions

Summer and fall

You have made it through the Ashe juniper-dense winter and the copious amounts of allergens blooming in the spring. Does that mean you are out of the woods for the rest of the year?

Flocke said mostly, but not quite. 

There are several types of elm varieties occurring in Texas. Some flower and pollinate in the spring, and others in the late summer and early fall. 

“Folks who are susceptible to Elm are lucky enough to have [allergies] both in the spring and early fall,” he said.

Similarly, there is the Rocky Mountain juniper that occurs in the western part of the state, which starts pollinating around October, Flocke said.